From e598a58e2ed26ef0f60a05a2d372f04539b84553 Mon Sep 17 00:00:00 2001
From: cinnaboot <cinnaboot@protonmail.com>
Date: Mon, 30 Nov 2020 11:03:53 -0500
Subject: [PATCH] add renDoRenderLoop interface

---
 examples/assimp_loading/main.cpp | 38 +-------------------------------
 include/renderer.h               |  8 +++++++
 src/renderer.cpp                 | 29 ++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 37 deletions(-)

diff --git a/examples/assimp_loading/main.cpp b/examples/assimp_loading/main.cpp
index ca798ff..5874c47 100644
--- a/examples/assimp_loading/main.cpp
+++ b/examples/assimp_loading/main.cpp
@@ -8,47 +8,11 @@
 #include "entity.h"
 
 
-typedef void (*frame_callback_fn) (render_state*);
-
-
 void
 doFrameCallback(render_state* rs)
 {
 }
 
-void
-doRenderLoop(render_state* rs, frame_callback_fn callback_fn)
-{
-	// TODO: move frame delay to renderFrame()
-	const uint TARGET_FPS = 60;
-	const uint FRAME_DELAY = 1000 / TARGET_FPS;
-	uint frameStart, frameTime;
-	bool running = true;
-	SDL_Event e;
-
-	while (running) {
-		frameStart = SDL_GetTicks();
-
-		// TODO: add a better structure for input, and provide a callback to use
-		// 	here
-		while (SDL_PollEvent(&e)) {
-			if ((e.type == SDL_KEYDOWN && e.key.keysym.sym == SDLK_ESCAPE)
-				|| e.type == SDL_QUIT) {
-				running = false;
-			}
-		}
-
-		callback_fn(rs);
-
-		renRenderFrame(rs);
-		SDL_GL_SwapWindow(rs->handles.window);
-		frameTime = SDL_GetTicks() - frameStart;
-
-		if (FRAME_DELAY > frameTime)
-			SDL_Delay(FRAME_DELAY - frameTime);
-	}
-}
-
 // TODO: remove/refactor this when we get animation working
 #include "animation_testing.cpp"
 
@@ -91,7 +55,7 @@ main()
 		// TODO: implement setting rotation from entity
 		//spaceship.rotation = glm::vec4(0, 0, 0, 0);
 
-		doRenderLoop(rs, doFrameCallback);
+		renDoRenderLoop(rs, 60, doFrameCallback);
 	} else {
 		LOG(Error) << "Error initializing entity, exiting\n";
 	}
diff --git a/include/renderer.h b/include/renderer.h
index c6b9ae8..91e0821 100644
--- a/include/renderer.h
+++ b/include/renderer.h
@@ -57,6 +57,14 @@ void renShutdown(render_state* rs);
 render_group*
 renAllocateGroup(uint entity_count, shader_program shader);
 
+//
+typedef void (*frame_callback_fn) (render_state*);
+
+void renDoRenderLoop(render_state* rs,
+	uint framerate = 60,
+	frame_callback_fn cb_func = nullptr);
+//
+
 void renRenderFrame(render_state* rs);
 
 bool
diff --git a/src/renderer.cpp b/src/renderer.cpp
index f9699be..8e862e0 100644
--- a/src/renderer.cpp
+++ b/src/renderer.cpp
@@ -105,6 +105,35 @@ renAllocateGroup(uint entity_count, shader_program shader)
 	return rg;
 }
 
+// TODO: add a better structure for input
+void
+renDoRenderLoop(render_state* rs, uint framerate, frame_callback_fn cb_func)
+{
+	uint delay = (framerate > 0) ? framerate : 0;
+	uint frameStart, frameTime;
+	bool running = true;
+	SDL_Event e;
+
+	while (running) {
+		frameStart = SDL_GetTicks();
+
+		while (SDL_PollEvent(&e)) {
+			if ((e.type == SDL_KEYDOWN && e.key.keysym.sym == SDLK_ESCAPE)
+				|| e.type == SDL_QUIT) {
+				running = false;
+			}
+		}
+
+		if (cb_func != nullptr) cb_func(rs);
+		renRenderFrame(rs);
+		SDL_GL_SwapWindow(rs->handles.window);
+		frameTime = SDL_GetTicks() - frameStart;
+
+		if (delay > frameTime)
+			SDL_Delay(delay - frameTime);
+	}
+}
+
 void
 renRenderFrame(render_state* rs)
 {